Femtosecond (fs) laser pulses are characterized by their high peak intensity, short duration and can be focused down to submicrometer-sized regions, enabling high-precision processing of virtually any material with reduced collateral damage. Moreover, also weakly focused pulses have the potential to produce nanometer structures that self-organize under certain irradiation conditions. Such structures, known as LIPSS (laser-induced periodic surface structures), are potential candidates for mimicking surface textures found in nature, on materials of technological interest, allowing their functionalization e.g. in terms of wettability, optical response, and wear resistance.
Here, we present different laser-fabricated surface structures that resemble the skin of moisture harvesting lizards and other reptiles. The fabrication process is based on a high-repetition rate fs laser (1030 nm, 350 fs, up to 2 MHz) and a galvo-scanner combined with a F-theta lens, allowing large-area processing. Different bio-mimetic structures are produced and morphological analysis reveals that their feature size and geometry strongly depends on the irradiation parameters, providing means to design novel and functional structures. In fact, we demonstrate that the wetting properties are strongly affected and can be controlled by tuning the irradiation conditions. The strategy presented here provides new perspectives for increasing fluid transport, improving biocompatibility, and tuning tribological properties of materials.